. >> the debate in 2004 between john kerry and george w. bush i, i literally forgot whether or not-- uh-oh, is this a new question or is this a follow-up question? my mind just went blank. and i had to make a decision. and i just guessed right. >> brown: the book highlights so-called major moments in debate history, the ones that come to define an dispnt sometimes ape candidate. george h.w. bush looking at his watch in 1992. >>Ñi thereçóñr guagain. >> brown: those zingers from ronald reagan that wounded jimmy cartener 1980. in the documentary "debating our destiny" jim went back to talk to candidates about their experience of the debates and had the chance to ask whether they prepared famous lines ahead of time. >> lehrer: i asked ronald reagan about, "there you go again," and a couple of others. "no, no, it just came to me." >> no it just seemed to be the thing to say and what he was saying up there. >> brown: did you believe him? >> lehrer: i don't know if i did or i didn't. i found it interesting that nobody wants to admit. >> brown: